JP6353457B2 - Biomass liquefaction via gas fermentation - Google Patents

Description

  The present invention relates generally to a process for producing products from microbial fermentation, particularly alcohol. In particular, the present invention relates to a method for producing fermentation products from industrial gases associated with biomass liquefaction. The present invention provides a method for producing at least one fermentation product by microbial fermentation of a gaseous substrate produced by a biomass liquefaction process such as roasting or pyrolysis.

Catalytic processes can be used to convert gases consisting primarily of CO and / or CO and hydrogen (H ₂ ) into various fuels and chemicals. Microorganisms can also be used to convert these gases into fuels and chemicals. These biological processes are generally slower than chemical reactions, but have several advantages over catalytic processes, including higher specificity, higher yields, lower energy costs and higher resistance to poisons Have

The ability of microorganisms to grow on CO as the sole carbon source was first discovered in 1903. This later uses the acetyl-coenzyme A (acetyl-CoA) biochemical pathway of autotrophic growth (also known as the Woods-Ljungdahl pathway and the carbon monoxide dehydrogenase / acetyl-CoA synthase (CODH / ACS) pathway) It was determined that it was the nature of the organism. Karubokishido nutritional (carboxydotrophic) organisms, photosynthetic organism, the majority of anaerobic organisms including methanogenic organisms and acetogenic organisms, various end product CO, _i.e., CO 2, _{H 2,} methane, n- butanol It has been shown to metabolize to acetate and ethanol. In addition to these products, we have found that some other useful products, carbon-based products, can be obtained by fermentation using specific microorganisms or microorganisms expressing specific genes. Proved before.

Anaerobic bacteria such as Clostridium bacteria have been demonstrated to produce ethanol from CO, CO ₂ and H ₂ via the acetyl CoA biochemical pathway. For example, various strains of Clostridium ljungdahlii that produce ethanol from gas are described in WO 00/68407, EP 117309, US Pat. Nos. 5,173,429, 5,593,886, and 6 368, 819, WO 98/00558 and WO 02/08438. The bacterium Clostridium autoethanogenum species are also known to produce ethanol from gas (Abrini et al., Archives of Microbiology 161, pp 345-351 (1994)).

Processes for the fermentation of substrates containing CO and H ₂ by microorganisms are known, but the possibilities for extending and integrating these processes into the industrial context have been little studied. Petrochemical plants and refineries produce large amounts of CO as a “by-product” byproduct. Significant proportion of the waste gas, (is burned) currently sent to flare or, alternatively have been used as a source of fuel, to produce a C_〇 ₂ greenhouse gas which is undesirable. Thus, it may be possible to improve industrial processes by utilizing the waste gas and energy produced thereby in fermentation to produce the desired product, while at the same time reducing gaseous carbon effluent from the factory.

  Biomass liquefaction can be an economical way to obtain valuable liquid products. The biomass can be any kind of woody biomass, agricultural waste, pulp and paper waste, municipal solid waste, or coal / coke. The three main processes for biomass conversion are roasting, pyrolysis and vaporization.

Roasting involves subjecting the biomass to a relatively low temperature (150-300 ° C.) in the absence of air or oxygen. Volatile material is made and then drained to produce a compressed carbon rich solid resembling coal. The generated gas stream comprising CO and CO _2.

  Pyrolysis is the thermochemical decomposition of organic materials at high temperatures (typically temperatures of 450-500 ° C. or higher) that do not involve oxygen. Pyrolysis is irreversible with simultaneous changes in chemical composition and physical phase. Pyrolysis can be characterized as “fast” or “slow” or somewhat intermediate describing the relative time under reaction conditions. Gaseous, liquid and solid products are produced in relative quantities depending on temperature and reaction time. Rapid pyrolysis maximizes liquid yield but is more challenging.

  Biomass vaporization involves the use of oxygen / air / steam to produce synthesis gas.

  It is an object of the present invention to provide an integrated method and / or system including biomass liquefaction and gas fermentation to produce useful products, or at least to provide useful options to the public. is there.

  The present invention generally provides a method for the production of a product, inter alia, by microbial fermentation of a CO-containing substrate.

In a first aspect, the present invention is a method for producing at least one product comprising:
i) providing a CO-containing substrate to a bioreactor comprising a culture of at least one carboxydotrophic acetic acid producing microorganism;
ii) fermenting the culture in a bioreactor to produce at least one fermentation product;
Wherein the substrate of step (i) is derived from one or more biomass liquefaction processes.

In certain embodiments, the CO-containing substrate further comprises CO ₂ and / or H ₂ .

  In certain embodiments, the CO-containing substrate is syngas.

  In certain embodiments, the synthesis gas is separated to provide a CO-containing substrate and a CO2 / H2 gas stream. In one embodiment, the CO-containing substrate is sent to a first bioreactor where it is fermented to produce an effluent gas stream comprising one or more alcohols and / or acids and CO2. In certain embodiments, the effluent gas stream further comprises hydrogen. In certain embodiments, the effluent gas stream is combined with a CO2 / H2 gas stream. In certain embodiments, the combined streams are sent to a second bioreactor containing a culture of one or more microorganisms and fermented to produce acetate.

  In certain embodiments, the one or more biomass liquefaction processes are selected from roasting, pyrolysis and vaporization. In one embodiment, the biomass liquefaction process is performed in a liquefaction zone.

In certain embodiments, the biomass liquefaction process is adapted to produce a liquefied gas product that is particularly suitable for use in a gas fermentation process. For example, increasing the temperature of the liquefaction process produces carbon monoxide preferentially over carbon dioxide. Fuet et al. Consider the variation between gas production, liquid production and charcoal production at various temperatures (Fu et al., Bioresource Technology, Vol. 102, Publication 17, September 2011, 8211- 8219). In certain embodiments, the liquefied gas product comprises CO at a concentration of about 20% to about 60%. In certain embodiments, the liquefied gas product contains CO ₂ at a concentration of 0% to about 40%. In certain embodiments, the liquefied gas product contains CO ₂ at a concentration of from 0% to 10%. In certain embodiments, the liquefied gas product comprises a mixture of gases comprising the above concentration of CO in combination with the above concentration of CO ₂ and / or the above concentration of H ₂ .

In a further specific embodiment, the liquefied gas product comprises an impurity selected from the group consisting of NH ₃ , NO, H ₂ S, HCN, SO ₂ and SO ₃ . In certain embodiments, at least a portion of the biomass used in the biomass liquefaction process comprises biomass recovered from the bioreactor.

  In certain embodiments, the energy generated during the liquefaction process can be used to increase the efficiency of the fermentation reaction and subsequent separation of the fermentation product. In certain embodiments, this energy is used to heat or cool the fermentation substrate or to allow separation of the fermentation product, for example, by distillation.

  In certain embodiments, the biomass liquefaction process includes pyrolysis and a pyrolysis product is produced. Preferably, the pyrolysis product is pyrolysis oil, charcoal and / or pyrolysis gas.

  In certain embodiments, at least a portion of the pyrolysis gas is sent to the bioreactor as part of the CO-containing substrate.

In certain embodiments, the pyrolysis oil is contacted with a hydrogen-containing effluent gas stream received from a bioreactor. If the CO-containing substrate provided to the bioreactor also contains H ₂ , the fermentation process will fix the CO component of the substrate, and optionally the CO ₂ component, thus resulting in an effluent gas stream having a higher concentration of hydrogen. When fermentation acts as an effective hydrogen film, as compared with the substrate provided to the bioreactor, through H ₂ is unconverted, it is possible to concentrate the H ₂ in effluent gas stream. Preferably, the effluent gas stream comprising hydrogen contacts the pyrolysis oil and hydrogenates the oil to produce a hydrocarbon product having 6 to 20 carbon atoms. In one embodiment, the hydrocarbon product is a high grade kerosene suitable for use as jet fuel (JP-5, JP-8) or other processes that require high purity kerosene. In certain embodiments, the effluent from the upgrade process can be a spent stream as a fuel source.

  In certain embodiments, the solid and / or liquid pyrolysis products undergo vaporization and at least a portion of the vaporized product is sent to the bioreactor as part of the CO-containing substrate. Preferably, the solid pyrolysis product is charcoal and the liquid pyrolysis product is pyrolysis oil.

In certain embodiments, the charcoal is converted in the presence of CO ₂ to form CO for addition to the CO-containing substrate. Preferably, CO ₂ for conversion is received from the bioreactor, roasting process and / or pyrolysis processes.

In certain embodiments, the biomass liquefaction process includes roasting. In certain embodiments, the roasting process produces one or more roasting gases comprising CO, CO ₂ and / or H ₂ . Preferably, at least a portion of the one or more roasting gases is added to the CO-containing substrate that is sent to the fermentation process.

  In certain embodiments, the one or more biomass liquefaction processes include roasting and pyrolysis. Preferably, the biomass is first subjected to roasting, then at least a portion of the at least one roasted product is subjected to pyrolysis, after which at least a portion of the at least one pyrolysis product is Added to a CO-containing substrate for use in gas fermentation.

In certain embodiments, the CO-containing substrate further comprises CO ₂ that is the product of a roasting, vaporization or pyrolysis process.

In certain embodiments, CO-containing substrate further includes roasting, and H ₂ is the product of thermal decomposition or vaporization process.

  In certain embodiments, the one or more fermentation products are alcohols or diols. In one embodiment, the alcohol is ethanol. In another embodiment, the diol is 2,3-butanediol. In certain embodiments, the one or more fermentation products are ethanol and 2,3-butanediol.

  In certain embodiments, one or more fermentation products are converted to one or more alkanes.

  In certain embodiments, the one or more arene compounds are obtained from pyrolysis oil. In further embodiments, one or more arene compounds are combined with one or more alkanes to produce a fuel.

In a second aspect, the present invention is a method for producing at least one product from a gaseous substrate comprising:
a. Biomass feedstock in a pyrolysis zone operating under conditions to produce a gaseous substrate comprising CO, CO ₂ and H ₂ and at least one pyrolysis product selected from the group consisting of pyrolysis oil and charcoal Sending
b. At least one part of the gaseous substrate is sent to a bioreactor comprising a culture of at least one carboxydotrophic acetic acid producing microorganism and at least a part of the gaseous substrate is subjected to anaerobic fermentation to produce at least one kind of fermentation Generating a waste stream comprising a product, a second biomass and an effluent gas stream comprising hydrogen;
c. Separating at least a portion of the second biomass from the waste stream;
d. Sending a portion of the second biomass to the pyrolysis zone;
A method comprising:

  In one embodiment, the effluent gas stream is sent to a separation zone operating under conditions to provide a hydrogen rich stream. In one embodiment, the pyrolysis product is a pyrolysis oil and the hydrogen rich stream and pyrolysis oil are sent to a hydrogenation zone operating under conditions to provide the hydrogenation product. In one embodiment, the hydrogenation product is a hydrocarbon having 6-20 carbons. In one embodiment, the hydrogenation zone operates under conditions to provide a jet fuel hydrocarbon product.

In one embodiment, the gaseous substrate from the pyrolysis zone comprising CO, CO ₂ and H ₂ operates under conditions to provide a CO ₂ rich stream and a concentrated CO and H ₂ gaseous substrate. Sent to the separation zone. In one embodiment, the concentrated CO and H ₂ stream is sent to a bioreactor.

In one embodiment, the pyrolysis product is charcoal and the charcoal and CO ₂ rich stream is sent to a reaction zone operating under conditions to produce a second substrate stream comprising CO. In one embodiment, a second substrate stream comprising CO is sent to the bioreactor.

  In one embodiment, the pyrolysis product is pyrolysis oil and / or charcoal, and the pyrolysis product is sent to a vaporization zone that operates under conditions to produce a vaporized CO-containing substrate.

  In one embodiment, biomass sent to the pyrolysis zone is first sent to the pretreatment zone. In one embodiment, the pretreatment zone is a roasting zone. In one embodiment, the biomass is sent to a roasting zone that operates under conditions to produce roasted biomass. The roasted biomass is then sent to the pyrolysis zone.

In a third aspect, the present invention is a method for producing at least one product from a gaseous substrate comprising:
a. Sending biomass raw material to the roasting zone to produce roasted biomass;
b. Sending the roasted biomass to a pyrolysis zone to produce a gaseous substrate comprising CO, pyrolysis oil and charcoal;
c. At least a portion of the gaseous substrate is sent to a bioreactor comprising a culture of at least one carboxydotrophic acetic acid producing microorganism, and at least a portion of the gaseous substrate is anaerobically fermented to produce at least one fermentation product Generating a waste stream comprising a second biomass and an effluent gas stream comprising hydrogen;
d. Separating at least a portion of the second biomass from the waste stream;
e. Sending an effluent gas stream to a separation zone operating under conditions to provide a hydrogen rich stream;
f. Sending a portion of the second biomass to the roasting zone;
g. Sending a pyrolysis oil and hydrogen rich stream to a hydrogenation zone operating under conditions to produce a hydrogenated product;
A method comprising:

  In one embodiment, the roasting process produces a gaseous byproduct stream comprising CO, at least a portion of which is sent to the bioreactor.

  In one embodiment, the charcoal is sent to the vaporization zone and vaporized to produce a second gaseous substrate comprising CO. In one embodiment, a second gaseous substrate comprising CO is sent to the bioreactor.

  In one embodiment, after mixing at least two of a gaseous byproduct stream, a second gas stream, or a gas stream selected from the group consisting of a gaseous substrate produced by a pyrolysis reaction, the bioreactor is mixed. Sent.

  In one embodiment, the hydrogenation product is a hydrocarbon product having 6-20 carbons. In one embodiment, the hydrogenation product is a high grade kerosene. In one embodiment, the hydrogenation zone operates under conditions to produce a hydrocarbon product for jet fuel.

  In a fourth aspect, the present invention is a system for the production of a fermentation product comprising a culture of one or more microorganisms adapted to produce a fermentation product by fermentation of a CO-containing substrate, A system is provided that includes a bioreactor adapted to receive at least a portion of a CO-containing substrate from one or more biomass liquefaction processes.

In certain embodiments, the CO-containing substrate further comprises CO ₂ and / or H ₂ .

  In certain embodiments, the one or more biomass liquefaction processes are selected from roasting, pyrolysis and vaporization. In certain embodiments, at least a portion of the biomass used in the biomass liquefaction process comprises biomass recovered from the bioreactor.

  In certain embodiments, the biomass liquefaction process includes pyrolysis, and the system further includes a pyrolysis zone adapted to produce a pyrolysis product. Preferably, the pyrolysis product is pyrolysis oil, charcoal and / or pyrolysis gas.

  In certain embodiments, the pyrolysis zone includes at least one outlet adapted to deliver at least a portion of the pyrolysis gas to the bioreactor.

In certain embodiments, the system further comprises:
a. Pyrolysis oil from pyrolysis reactor;
b. A hydrogenation zone is included that is adapted to receive an effluent gas stream comprising hydrogen from the bioreactor.

  In certain embodiments, the effluent gas stream is returned to the pyrolysis zone. In certain embodiments, the effluent gas stream is used as a fuel source.

  In certain embodiments, the system further includes a vaporization zone adapted to receive solid and / or liquid biomass and adapted to deliver the vaporized product to the bioreactor as part of the CO-containing substrate. . Preferably, the solid and / or liquid biomass is a pyrolysis product received from the pyrolysis zone. Preferably, the solid pyrolysis product is charcoal and the liquid pyrolysis product is pyrolysis oil.

In certain embodiments, the system further includes a roasting zone adapted to subject the biomass to roasting to produce roasted biomass, and one or more types comprising CO, CO ₂ and / or H ₂ . An outlet adapted to send at least a portion of the roasting gas to the bioreactor;

  In certain embodiments, the pyrolysis zone is adapted to receive at least a portion of the roasted biomass.

In certain embodiments, the pyrolysis zone, roasting zone and / or vaporization zone further includes one or more outlets adapted to deliver at least a portion of the one or more gas products to the bioreactor. Preferably the gas product comprises CO, CO ₂ and / or H ₂ .

In certain embodiments, the system, in order to form a CO for addition to the CO-containing substrate comprises coal conversion zone adapted to convert the coal in the presence of CO _2. Preferably, CO ₂ for conversion bioreactor, roasting reactor, received via gas recirculation conduit from the vaporization module and / or pyrolysis reactor.

  In a fifth aspect, the present invention provides a fermentation product when produced by the method of any of the first, second or third aspects, or the system of the fourth aspect.

  The following embodiments can be applied to any of the aspects provided herein.

  In one embodiment, the carboxydotrophic acetic acid producing microorganism is from the genus Clostridium. In one embodiment, the carboxydotrophic acetic acid producing microorganism is selected from the group consisting of Clostridium autoethanogenum, Clostridium ljungdahlii, Clostridium ragsdalei, and Clostridium coskatati. In one particular embodiment, the microorganism is Clostridium autoethanogenum DSM23693. In another specific embodiment, the microorganism is Clostridium ljungdahlii DSM13528.

  In one embodiment, the fermentation product is an alcohol or diol. In one embodiment, the alcohol is ethanol. In another embodiment, the diol is 2,3-butanediol. In certain embodiments, the one or more fermentation products are ethanol and 2,3-butanediol. In one embodiment, acetic acid is produced as a fermentation byproduct.

  In one embodiment, the present invention provides one or more alkanes obtained as a derivative of one or more fermentation products. In one embodiment, the one or more fermentation products are further converted to downstream products by known conversion methods such as thermochemical conversion methods or catalytic conversion methods.

  In one embodiment, the present invention provides one or more arene compounds obtained as a derivative of a pyrolysis oil produced according to a method according to any of the above aspects. In certain embodiments, one or more arene compounds are combined with one or more alkanes to produce a fuel.

  The invention is present individually in the parts, elements and features mentioned or shown in the specification of the present application, or collectively in any or all combinations of two or more of said parts, elements or features. It can also be said broadly that, where specific integers having equivalents known in the art to which the present invention pertains are described herein, such known equivalents are those individually listed. As being incorporated herein.

  These and other aspects of the invention that should be considered in all its novel aspects will become apparent from the following description, given by way of example only, with reference to the accompanying drawings.

2 is an exemplary integration scheme illustrating the system of the present invention including a biomass liquefaction process. 3 is an exemplary integrated scheme illustrating a system and method for producing one or more products by fermentation of a gaseous substrate derived from a biomass liquefaction process according to a second aspect of the present invention.

Definitions The following is a description of the invention given in general terms, including preferred embodiments.

  The “fermentation broth” referred to herein is a medium containing at least a nutrient medium and bacterial cells.

  Terms such as “increased efficiency” and “increased efficiency” when used in connection with a fermentation process, the growth rate of microorganisms that catalyze the fermentation, the growth rate and / or production at elevated product concentrations. Product production rate, volume of desired product produced per volume of substrate consumed, production rate or level of desired product, and desired product produced compared to other by-products of fermentation Including, but not limited to, an increase in one or more of the relative proportions of

  The phrase “substrate comprising carbon monoxide” and similar terms should be understood to include any substrate, eg, carbon monoxide therein is one or more types for growth and / or fermentation. Available for various bacterial strains. The substrate may be a “gaseous substrate containing carbon monoxide”, and similar phrases and terms include any gas that contains some carbon monoxide. In certain embodiments, the substrate comprises at least about 20% to about 100%, 20% to about 70%, 30% to about 60%, and 40% to about 55% CO by volume. including. In certain embodiments, the substrate is about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, or about 60% by volume. Of CO.

It is not necessary to contain hydrogen to substrate, the presence of H ₂ is not deleterious to product formation by the method of the present invention. In certain embodiments, the presence of hydrogen results in alcohol production with improved overall efficiency. For example, in certain embodiments, the H ₂ : CO ratio of the substrate can be about 2: 1, 1: 1, or 1: 2. In one embodiment, the substrate comprises about 30% or less, 20% or less, about 15% or less, or about 10% or less H ₂ by volume. In other embodiments, the substrate stream comprises a low concentration, eg, less than 5%, less than 4%, less than 3%, less than 2%, or less than 1% H ₂ or substantially free of hydrogen. . The substrate may comprise about 1% to about 80% by volume, or 1 percent by volume to about 30% by volume of CO ₂ some CO _2, such as also. In one embodiment, the substrate comprises about 20% or less CO ₂ by volume. In certain embodiments, the substrate is about 15 vol% or less, about 10 vol% or less, or about 5% by volume of CO _2, or substantially free of CO _2.

  In the following description, embodiments of the present invention are described in terms of “CO-containing gaseous substrate” delivery and fermentation. However, it should be understood that the gaseous substrate may be provided in alternative forms. For example, the CO-containing gaseous substrate may be provided dissolved in a liquid. In essence, the liquid is saturated with a carbon monoxide containing gas, after which the liquid is added to the bioreactor. This can be achieved using standard methods. As an example, a microbubble dispersion generator (Hensirisak et. Al. Scale-up of microbubble disperser generator for aerobic fermentation; Applied Biochemistry and Biotechnology. As a further example, the CO-containing gaseous substrate may be adsorbed on a solid support. Such alternative methods are encompassed by the use of terms such as “CO-containing substrate”.

  In certain embodiments of the invention, the CO-containing gaseous substrate is an industrial off-gas or waste gas. “Industrial waste gas or off-gas” includes any gas containing CO produced by an industrial process, including ferrous metal product production, non-ferrous product production, petroleum refining process, coal vaporization, biomass vaporization, power production, It should be broadly construed to include carbon black production and gas produced as a result of coke production. Further examples can be provided elsewhere herein.

  Unless the context requires otherwise, terms such as “fermentation”, “fermentation process” or “fermentation reaction” as used herein encompass both the growth phase and the product biosynthesis phase of the process. Is intended to be. In some embodiments, the bioreactor may include a first growth reactor and a second or additional fermentation reactor. Thus, the addition of a metal or composition to a fermentation reaction should be understood to include adding to any one of these reactors.

  The term “bioreactor” is suitable for continuous stirred tank reactor (CSTR), immobilized cell reactor (ICR), trickle bed reactor (TBR), bubble column, gas lift fermenter, static mixer, or gas-liquid contact It includes one or more containers containing other containers or other equipment and / or fermentation equipment consisting of towers or piping. In some embodiments, the bioreactor may include a first growth reactor and a second or additional fermentation reactor. Thus, when referring to the addition of a substrate to a bioreactor or fermentation reaction, it should be understood to include adding to any one of these reactors as needed.

DESCRIPTION The inventors have surprisingly found that an integrated system including a biomass liquefaction process and a gas fermentation process can be used to produce useful fermentation products. The biomass liquefaction process can be adapted to produce a gaseous substrate that is particularly suitable for use in a gas fermentation process.

CO and CO ₂ and / or H ₂ are captured or derived from the biomass liquefaction process using any convenient method. Depending on the composition of the gaseous substrate, it may be desirable to treat it to remove unwanted impurities prior to introduction into the fermentation. For example, the substrate may be filtered or washed using known methods. However, the inventors have found that the microbial culture used for fermentation has a surprisingly high resistance to impurities that may be found in the liquefied product. Although the liquefied gas product appears to be relatively impure and unsuitable for use in microbial fermentation, the fermentation actually proceeds and can produce a useful fermentation product.

Furthermore, the final and relative concentrations of CO, CO ₂ and / or H _{2 in} the gas can be optimized for microbial fermentation by adjusting certain liquefaction process parameters. For example, by maintaining a lower temperature during the liquefaction process, the liquid yield can be maximized. However, using higher temperatures during the liquefaction process results in an increase in CO content. This increase in CO can be beneficial to the fermentation process because an increase in CO gas at this stage allows for an increase in ethanol yield during the fermentation process.

Microbial biomass The present invention also provides an integrated system for the recycling of biomass from fermentation. In this embodiment of the invention, at least a portion of the biomass used in the biomass liquefaction process comprises biomass recovered from the bioreactor. The recovered biomass consists mainly of dead cell material from microbial cultures.

  Biomass is removed and recycled and processed by one or more biomass liquefaction processes such as those described herein. It may be desirable to treat the removed biomass prior to liquefaction to remove moisture, fermentation products, or otherwise modify its properties.

  Known liquefaction processes often use biomass, including agricultural waste and other common biomass sources. However, these raw materials often contain particle sizes that are too large for optimal liquefaction treatment. The present invention provides biomass feedstock recovered from microbial fermentation. This fermented biomass has a small particle size, and can be easily prepared as a dry pulverized biomass raw material suitable for efficient liquefaction treatment.

Roasting Roasting is a thermochemical treatment of biomass in the range of 150-340 ° C. in the absence of oxygen. In this process, the biomass (especially hemicellulose) decomposes and partially produces various types of volatile materials. The remaining roasted biomass (solid) has an energy content greater than about 30% per mass unit. The roasting process produces CO, CO ₂ and / or H ₂ that can be used in the fermentation processes described herein. In certain embodiments, at least a portion of the one or more roasting gases is added to the CO-containing substrate and sent to the fermentation process.

In certain embodiments, the one or more biomass liquefaction processes include roasting and pyrolysis. Preferably, the biomass is first subjected to roasting to produce roasted biomass, after which at least a portion of the roasted biomass is subjected to pyrolysis. At least one gaseous product of the pyrolysis process is sent to the bioreactor. In one embodiment, at least one gaseous product of the pyrolysis process is added to a CO-containing substrate produced by a roasting process. In one embodiment, the at least one gaseous product of the pyrolysis process is selected from the group consisting of CO, CO ₂ and H ₂ .

In certain embodiments, the CO-containing substrate further comprises CO ₂ that is the product of a roasting, vaporization or pyrolysis process.

In certain embodiments, CO-containing substrate further containing H ₂ is pyrolysis or roasting, the product of the vaporization process.

In certain embodiments, the system further includes a roasting zone adapted to subject the biomass to roasting to produce roasted biomass, and one or more types comprising CO, CO ₂ and / or H ₂ . An outlet adapted to send at least a portion of the roasting gas to the bioreactor;

  In one embodiment, the pyrolysis zone is adapted to receive at least a portion of the roasted biomass from the roasting zone.

In certain embodiments, the pyrolysis zone, roasting zone and / or vaporization zone further includes one or more outlets adapted to deliver at least a portion of the one or more gas products to the bioreactor. Preferably the gas product comprises CO, CO ₂ and / or H ₂ .

In one embodiment, the gaseous product produced by any one of the roasting zone, pyrolysis zone, or vaporization zone is a separation zone that operates to separate at least a portion of the gas stream (s). Sent to. In one embodiment, the separation zone operates under conditions for separating CO ₂ from the gas stream and produces a CO ₂ rich stream and a CO and H ₂ rich stream.

Pyrolysis In certain embodiments, the biomass liquefaction process includes pyrolysis. The pyrolysis process produces a CO-containing gaseous substrate and pyrolysis products. The pyrolysis product is selected from the group consisting of pyrolysis oil and charcoal. Pyrolysis produces these products from biomass by heating the biomass in a hypoxic / anoxic environment. In the absence of oxygen, combustion can be prevented. The relative yield of product from pyrolysis varies with temperature. Temperatures of 400-500 ° C (752-932 ° F) produce more char, but temperatures above 700 ° C (1,292 ° F) favor liquid and gaseous fuel component yields.

  Pyrolysis occurs at higher temperatures, typically more quickly in seconds rather than time. High temperature pyrolysis, also known as vaporization, mainly produces synthesis gas. Typical yields are 60% pyrolysis oil (also known as biooil), 20% biochar, and 20% syngas. In comparison, slow pyrolysis can produce substantially more charcoal (about 50%). When initialized, both processes generate net energy. For typical inputs, the energy required to run a “fast” pyrolysis device is about 15% of the energy it produces.

  In certain embodiments, the energy generated during the liquefaction process may be used to increase the efficiency of the fermentation reaction and subsequent separation of the fermentation product. In certain embodiments, this energy is used to heat or cool the fermentation substrate or to allow separation of the fermentation product, for example, by distillation.

  “Fast” pyrolysis has the advantage of operating at atmospheric pressure and moderate temperatures (400-500 ° C.). The yield of pyrolysis oil can exceed 70% w / w. There are several types of fast pyrolysis furnaces that can be used in the present invention. Particular embodiments include a reactor selected from the group consisting of a bubbling fluidized bed, a circulating fluidized bed / transport furnace, a rotating cone pyrolysis device, an ablation pyrolysis device, a vacuum pyrolysis device, and an Auger reactor. . Fluidized bed reactors having either a bubbling medium or a circulating medium are most commonly used for fast pyrolysis. Auger reactors are used because of their simplicity and ease of control, but they cannot achieve the rapid exotherm obtained with fluidized bed reactors. Sadaka and Boateng (2009) outline the types of reactors used for pyrolysis.

During the pyrolysis process, the organic components of the biomass (ie, cellulose, hemicellulose, and lignin) are decomposed and depolymerized to form a mixture of vapor and micron-sized droplet aerosols. Extending the reaction time promotes aerosol secondary reactions and increases the formation of low molecular weight hydrocarbons (eg, CH ₄ , C ₂ H _6, etc.) and synthesis gas (CO and CO ₂ and / or H ₂ ). To do. Pyrolysis oil is formed by rapid cooling and concentration of the mixture. In certain embodiments, at least a portion of the pyrolysis gas is sent to the bioreactor as part of the CO-containing substrate.

Pyrolyzed oils (generally represented by C ₆ H ₈ O ₄ ) are oxygenated organic compounds (eg acids, alcohols, aldehydes, esters, furans, ketones, sugars, phenols and many Polyfunctional compound) and a complex mixture of water (typically about 15-30% w / w). On an elemental basis, it is compositionally similar to the parent biomass and is therefore sometimes referred to as “liquid plant material”.

  Pyrolysis oil derived from biomass is rich in carbon and can be refined in the same manner as crude oil. Compared to solid biomass materials, with ease of transportation and storage, pyrolysis oil can serve as a potential feedstock for the production of fuels and chemicals in petroleum refining. Pyrolysis oil may be used to produce biofuel including transportation fuel. Although pyrolysis oil may be used in untreated form, post-treatment may be desirable to optimize the pyrolysis oil for a particular application.

  In certain embodiments, the pyrolysis oil is vaporized prior to use with the fermentation substrate.

  Pyrolytic oil contains lower amounts of trace metals and sulfur is particularly useful as a low emission combustion fuel. Recovery of pyrolysis oil from the pyrolysis process and separation from byproducts such as charcoal may be performed according to known methods.

  The relatively high oxygen content of pyrolysis oil reduces the calorific value compared to most fossil fuels (eg, about half the calorific value of heavy oil). This high oxygen content and moisture content can make pyrolysis oils inferior to conventional hydrocarbon fuels in certain situations. In addition, liquid phase separation and polymerization, and container erosion make storage of these liquids difficult.

  The pyrolysis oil modification can be used to convert the pyrolysis oil to gasoline by mild hydrotreating followed by hydrocracking. Such methods are known in the art. However, hydrogen production is capital intensive and it is desirable to develop a method that increases hydrogen production and recovery efficiency, especially from low purity streams. In the absence of hydrogen recovery, such a stream ends with fuel gas or is sent to a flare, and expensive hydrogen components are efficiently wasted.

The present invention provides a method and system in which an effluent gas stream comprising H ₂ is sent from a fermentation bioreactor to a hydrogenation zone where it receives pyrolysis oil from the pyrolysis zone. H ₂ comes into contact with the pyrolysis oil and hydrogenates the oil to produce a hydrocarbon product. The hydrocarbon product has 6 to 20 carbons. In one embodiment, the hydrocarbon product is a high grade kerosene. In one embodiment, the hydrogenation zone operates under conditions to produce a hydrocarbon product for jet fuel. In one embodiment, the hydrogenation occurs in a steam reformer module.

In certain embodiments, the pyrolysis oil is contacted with an effluent gas stream comprising hydrogen received from the bioreactor. The CO-containing substrate is fed to the bioreactor. This substrate includes gases that may have been produced as a by-product of the pyrolysis process or alternative biomass liquefaction process. In certain embodiments, CO-containing substrate also comprises _{H 2.} The fermentation process fixes the CO component of this substrate and optionally at least a portion of the CO ₂ component, thus resulting in an effluent gas stream having a higher concentration of hydrogen.

The present invention provides a method and system that uses a fermentation reaction as a hydrogen purifier and then uses hydrogen to improve the pyrolysis oil to a superior quality biofuel. These high quality end products do not require expensive storage or transportation of pyrolysis oil and require high purity hydrogen that is obtained and stored for use in the pyrolysis oil modification process. Can be generated without. When fermentation acts as an effective hydrogen film, as compared with the substrate provided to the bioreactor, through H ₂ is unconverted, it is possible to concentrate the H ₂ in effluent gas stream.

If the effluent stream contains H ₂ and unacceptable levels of impurities or other gas species, further refining may be desirable prior to pyrolysis oil improvement. Purification methods are known to those skilled in the art and may involve the use of a pressure swing adsorption process. A pressure swing adsorption (PSA) process may be used to recover hydrogen from an impure stream or to increase the purity of the hydrogen in the stream. The gas stream containing H ₂ enters a molecular sieve system that adsorbs CO ₂ , CO, CH ₄ , N ₂ and H ₂ O at high pressure. Hydrogen is able to pass through the sieve is collected (higher yields are associated with purity of lower final H ₂ product) at about 65 to 90% yield. When saturated, the sieve is depressurized, after which the desorption gas is purged with the smallest possible amount of hydrogen product. Since large amounts of adsorbed species are released at lower regeneration pressures, the extent of regeneration is a function of pressure. This in turn leads to more hydrogen recovery. Thus, a regeneration pressure close to atmospheric pressure maximizes hydrogen recovery. The vessel is then repressurized with hydrogen prepared for the next period as an adsorbent. Commercial systems typically have three or four containers to provide smooth operation. Typical gas flow produced from the PSA step may include the following: _{H 2} (about 7~27%), _CO 2, _CO and _CH 4.

Vaporization In certain embodiments, the solid and / or liquid feed is vaporized in a vaporization zone adapted to receive solid and / or liquid biomass. At least a portion of the vaporized product is sent to the bioreactor as part of the CO-containing substrate. In certain embodiments, the feedstock is a solid pyrolysis product, such as charcoal, or a liquid pyrolysis product, such as pyrolysis oil.

At the time of vaporization, the raw material goes through the following process.
a. Dehydration occurs at about 100 ° C. Typically, the resulting vapor is mixed in a gas stream, and subsequent chemical reactions can be particularly involved in water gas reactions when the temperature is high enough (see step 5).
b. The pyrolysis process occurs at about 200-300 ° C. Volatile materials are released and char is produced, resulting in a weight loss of up to 70% for the coal. This process depends on the properties of the carbonaceous material, determines the charcoal structure and composition, and then undergoes a vaporization reaction.
c. The combustion process occurs as a volatile product, and some of the charcoal reacts with oxygen to form mainly carbon dioxide and a small amount of carbon monoxide, providing heat for the subsequent vaporization reaction.
d. Vaporization occurs when charcoal reacts with carbon, steam and CO ₂ to produce carbon monoxide and hydrogen. Furthermore, the reversible gas phase water gas shift reaction reaches equilibrium at a very high rate at the temperature in the vaporizer. This balances the concentrations of carbon monoxide, steam, carbon dioxide and hydrogen.

Charcoal conversion Charcoal is a solid charcoal produced by pyrolysis of biomass. Charcoal is called biochar when used for specific purposes, such as soil improvement, to increase soil fertility, increase agricultural productivity, or improve low grade soil be able to. The use of charcoal can reduce deforestation and has been regarded as a way to mitigate global warming through carbon sequestration.

  Charcoal quality varies depending on the source and production process. When used as a soil conditioner, charcoal improves water quality, reduces soil emissions of greenhouse gases, reduces nutrient leaching, reduces soil acidity, and reduces irrigation and fertilizer requirements can do.

  The present invention also provides a fermentation process that includes the use of a CO-containing substrate, wherein at least a portion of the substrate is produced by a charcoal conversion process.

Charcoal, in the presence of CO _2, undergo conversion in coal conversion module to form CO. Preferably, CO ₂ for conversion bioreactor, roasting zone, from the vaporization zone and / or pyrolysis zone via the gas recirculation conduit are received in a coal conversion module.

Products The present invention provides fermentation products produced by the methods and systems disclosed herein. In certain embodiments, the fermentation product is an alcohol or diol. In one embodiment, the alcohol is ethanol. In another embodiment, the diol is 2,3-butanediol. In certain embodiments, the one or more fermentation products are ethanol and 2,3-butanediol. Downstream processing of the fermentation product can produce derivatives such as alkanes or other hydrocarbons.

  The present invention also provides one or more arene compounds obtainable by treatment of pyrolysis oil with the methods and systems described herein. In certain embodiments, one or more arene compounds can be combined with alkanes to produce other fuels and compounds, particularly transportation fuels.

  It should be understood that in addition to the CO-containing substrate gas, an appropriate liquid nutrient medium needs to be supplied to the bioreactor for bacterial growth and production of the resulting product.

  In certain embodiments, the fermentation occurs in an aqueous medium. In certain embodiments, the fermentation of the substrate occurs in a bioreactor.

  Substrate and media may be fed to the bioreactor in a continuous batch mode or batch feed mode. The nutrient medium contains enough vitamins and minerals to allow the growth of the microorganisms used. Anaerobic media suitable for fermentation using CO are known in the art. For example, suitable media are described in Biebel (2001). In one embodiment of the invention, the culture medium is that described in the Examples section later in this specification.

Typically, CO is added to the fermentation reaction in the gaseous state. However, the method of the present invention is not limited to the addition of the substrate in this state. For example, carbon monoxide can be provided in a liquid. For example, the liquid may be saturated with a carbon monoxide containing gas and the liquid added to the bioreactor. This may be achieved using standard methodologies. As an example, a microbubble dispersion generator (Hensirisak et. Al. Scale-up of microbubble dispersion generator for aerobic fermentation), Applied Biochemistry and Biotechnology. be able to. When "gas stream" is referred to herein, the term also encompasses other forms of transporting the gaseous components of that stream, such as the saturated liquid method described above.

Gaseous substrate The CO-containing substrate is at least about 20 volume% to about 100 volume% CO, 40 volume% to 95 volume% CO, 40 volume% to 60 volume% CO, and 45 volume% to 55 volume%. It may contain any proportion of CO such as CO. In certain embodiments, the substrate is about 25%, about 30%, about 35%, about 40%, about 45%, or about 50%, about 55%, or about 60% by volume. % CO. Substrates with lower concentrations of CO, such as 2%, may also be appropriate, especially when H ₂ and CO ₂ are also present.

The presence of H ₂ is not deleterious to hydrocarbon product formation by fermentation. In certain embodiments, the presence of hydrogen improves the overall efficiency of alcohol production. For example, in certain embodiments, the H ₂ : CO ratio of the substrate can be about 2: 1, 1: 1, or 1: 2. In other embodiments, the CO-containing substrate is less than about 30%, less than 27%, less than 20%, less than 10%, or a lower concentration of H ₂ , eg, less than 5%, less than 4%, less than 3%, less than 2%, or either containing H ₂ of less than 1%, or substantially free of hydrogen. In yet another embodiment, CO-containing substrate is more than 50%, more than 60%, greater than 70%, greater than 80%, or containing _{H 2} greater than 90%. The substrate may include some CO ₂ , for example, about 1% to about 80% by volume CO ₂ , or 1% to about 30% by volume CO ₂ .

Fermentation conditions and microorganisms Processes for producing ethanol and other alcohols from gaseous substrates are known. Exemplary processes include, for example, WO 2007/117157, WO 2008/11080, WO 2009/022925, WO 2009/064200, US Pat. Nos. 6,340,581, 6,136,577, 5 , 593,886, 5,807,722, and 5,821,111, each of which is incorporated herein by reference.

  The fermentation should desirably be performed under fermentation conditions suitable for producing a fermentation product that is desired to occur. Reaction conditions to be considered include pressure, temperature, gas flow rate, liquid flow rate, medium pH, medium redox potential, stirring rate (when using a continuous stirred tank reactor), inoculation level, in liquid phase A maximum gas substrate concentration to ensure that the CO is not rate limiting and a maximum product concentration to avoid product inhibition are included.

  Furthermore, it is often desirable to increase the CO concentration of the substrate stream (or CO partial pressure in the gaseous substrate) to increase the efficiency of the fermentation reaction in which CO is the substrate. Operating at elevated pressures can significantly increase the rate of transfer from the gas phase to the liquid phase of CO that can be taken up by microorganisms as a carbon source for fermentation production. This in turn means that the retention time (defined as the liquid volume in the bioreactor divided by the input gas flow rate) can be reduced if the bioreactor is maintained at a pressure higher than atmospheric pressure. Optimal reaction conditions will depend in part on the particular microorganism of the invention used. In general, however, fermentation is preferably carried out at a pressure higher than ambient pressure. Also, the rate of conversion of a given CO to product is partly a function of substrate retention time, and thus achieving the desired residence time will determine the required volume of the bioreactor, so By using it, the required capacity of the bioreactor can be greatly reduced, and as a result, the capital cost of the fermentation apparatus can be greatly reduced. By way of example given in US Pat. No. 5,593,886, the volume of the reactor can be reduced in proportion to an increase in the operating pressure of the reactor, ie a bioreactor operating at a pressure of 10 atmospheres Only one tenth of the volume of a bioreactor operated at 1 atmosphere is required.

  As an example, the advantages of performing fermentation from gas to ethanol at high pressure are described. For example, WO 02/08438 describes a gas-to-ethanol fermentation carried out under pressures of 30 psig and 75 psig, with ethanol productivity of 150 g / l / day and 369 g / l / day, respectively. However, for example, it has been found that fermentation carried out at atmospheric pressure using a similar medium and influent gas composition produces 10-20 times less ethanol per liter per day.

  It is also desirable that the rate of introduction of the CO-containing gaseous substrate is such that it ensures that the concentration of CO in the liquid phase is not rate limiting. One or more products are consumed by the culture because CO can be the result of limited conditions.

The composition of the gas stream used to feed the fermentation reaction can have a significant impact on the efficiency and / or cost of the reaction. For example, O ₂ can reduce the efficiency of the anaerobic fermentation process. Undesirable or unnecessary gas treatment at the stage of the fermentation process before and after fermentation can increase the loading of such stages (e.g. unnecessary if the gas stream is compressed before entering the bioreactor). Can be used to compress gases that are not needed for fermentation). Accordingly, it may be desirable to treat a substrate stream, particularly a substrate stream from an industrial source, to remove unwanted components and increase the concentration of the desired component.

  In certain embodiments, the culture of the microorganism as defined herein is maintained in an aqueous medium. Preferably, the aqueous medium is a minimal medium for anaerobic microbial growth. Suitable media are known in the art and are described, for example, in US Pat. Nos. 5,173,429, 5,593,886 and WO 02/08438, and are described in the Examples below. As described in the section.

  In certain embodiments, the microorganism, Clostridium autoethanogenum, Clostridium ljungdahlii, Clostridium ragsdalei, Clostridium carboxidivorans, Clostridium drakei, Clostridium scatologenes, Clostridium aceticum, Clostridium formicoaceticum, Clostridium magnum, Butyribacterium methylotrophicum, Acetobacterium woodii, Alkalibaculum bacchii, Blautia producta, Eubacterium lim sum, Moorella thermoacetica, Moorella thermautotrophica, Sporomusa ovata, Sporomusa silvacetica, Sporomusa sphaeroides, is selected Oxobacter pfennigii, and from the group of Karubokishido nutritional acetogenic microorganisms including Thermoanaerobacter kiuvi.

  In one particular embodiment, the parental microorganism is C.I. autoethanogenum, C.I. ljungdahlii, and C.I. It is selected from a cluster of ethanologenic acetic acid-producing clostridial species including ragsdalei species as well as related isolates. These include C.I. autoethanogenum JAI-1T (DSM10061) [Abrini J, Naveau H, Nyns EJ: Clostridium autoethanogenum, sp. nov. , Anaerobic bacteria that produce ethanol monoxide (Arch Microbiol 1994, 4: 345-351), C.I. autoethanogen LBS 1560 (DSM 19630) [Simpson SD, Forster RL, Tran PT, Rowe MJ, Warner IL: Novel bacteria and methods thereof (Novell bacteria and methods theleof), International Patent Publication No. 2009/200, WO / 200, C0. autoethanogenum LBS 1561 (DSM23693), C.I. ljungdahlii PETCT (DSM13528 = ATCC55383) [Tanner RS, Miller LM, Yang D: Clostridium ljungdahlii sp. nov. Acetic acid-producing species in Clostridium rRNA homology group I (An Acetogenic Specialties in Clostri rRNA Homology Group I), Int J Systact Bacteriol 1993, 43: 232-236], C.I. ljungdahlii ERI-2 (ATCC 55380) [Gaddy JL: Clostridium stain what products acetic acid from waste gasses, U.S. Patent No. 5,593,886, U.S. Patent No. 5,593,886]. ljungdahlii C-01 (ATCC 55988) [Gaddy JL, Clausen EC, Ko C-W: Microbial process for the preparation acid acid as a preparation of acetic acid and solvent for extraction from fermentation broth. solvent for it extraction from the formation broth), US Pat. No. 6,368,819, 2002], C.I. ljungdahlii O-52 (ATCC 55989) [Gaddy JL, Clausen EC, Ko C-W: Microbial process for the preparation acid acid as a preparation of acetic acid and solvent for extraction from fermentation broth. solvent for it extraction from The formation broth), US Pat. No. 6,368,819, 2002], C.I. ragsdalei P11T (ATCC BAA-622) [Huhnke RL, Lewis RS, Tanner RS: Isolation and characterization of novel Clostridium species (Isolation and Characteristic of novel Crossspecies) 200 / International Patent No. 80 / WO 55 / WO For example, "C. coskatati" [Zahn et al.-New ethanologenic species Clostridium coskatii (US Patent Application No. 2011/0229947)] and "Clostridium sp." 1-12), or mutant strains such as C.I. ljungdahlii OTA-1 (Tirado-Acevedo O. Clostridium ljungdahlii, bioethanol production from synthesis gas (Production of Bioethanol from Synthesis Gaslih) It is not limited to. These strains form sub-clusters within the clostridial rRNA cluster I, and their 16S rRNA genes are over 99% identical and have a GC content of about 30% as well. However, DNA-DNA reassociation and DNA fingerprinting experiments showed that these strains belonged to different species [Hunnke RL, Lewis RS, Tanner RS: Isolation and Characterization of Novel Clostridial Species (Isolation and Characterization of novel Clostrial Species) International Patent WO 2008/028055, 2008). All species of this cluster have similar morphology and size (logarithmically growing cells are 0.5-0.7 × 3-5 μm) and mesophilic (optimal growth temperature of 30-37 ° C.) [Tanner RS, Miller LM, Yang D: Clostridium ljungdahlii sp. nov. , Acetic acid species in Clostridium rRNA homology group I (An Acetogenic Species in Clos rial Homology Group I), Int J Systact Bacteriol 1993, 43: 232-236; Abrin J, Nave C autoethanogenum, sp. nov. , Anaerobic bacteria that produce ethanol from carbon monoxide (Arch Microbiol 1994, 4: 345-351; Hunnke RL, Lewan tri RS RS) (Isolation and Characteristic of novel Crossspecial Species)], International Patent WO 2008/028055, 2008]. Furthermore, they all have strong phylogenetic features such as a similar pH range (pH 4-7.5, optimal initial pH 5.5-6), strong independence on CO-containing gases with similar growth rates. Vegetative growth and share a similar metabolic profile where the main fermentation end products are ethanol and acetic acid, and small amounts of 2,3-butanediol and lactic acid are formed under certain conditions [Tanner RS, Miller LM, Yang D: Clostridium ljungdahlii sp. nov. , Acetic acid species in Clostridium rRNA homology group I (An Acetogenic Species in Clos rial Homology Group I), Int J Systact Bacteriol 1993, 43: 232-236; Abrin J, Nave C autoethanogenum, sp. nov. , Anaerobic bacteria that produce ethanol from carbon monoxide, Arch microbiol 1994, 4: 345-351; Hunnke RL, Lewis Tris RS new species RS Characterization (Isolation and Characterization of novel Crossspecial Species), International Patent WO 2008/028055, 2008]. Indole formation was also observed in all three species. However, these species may contain various sugars (eg, rhamnose, arabinose), acids (eg, gluconic acid, citric acid), amino acids (eg, arginine, histidine), or other substrates (eg, betaine, butanol). ) Substrate use. Furthermore, some of these species have been found to be auxotrophic for certain vitamins (eg thiamine, biotin), while other species have not.

  In one embodiment, the parental microorganism is Clostridium autoethanogenum or Clostridium ljungdahlii. In one particular embodiment, the microorganism is Clostridium autoethanogenum DSM23693. In another specific embodiment, the microorganism is Clostridium ljungdahlii DSM13528 (or ATCC 55383).

  Fermentation can be any suitable bioreactor configured for gas / liquid contact, such as a continuous stirred tank reactor (CSTR), an immobilized cell reactor, capable of contacting a substrate with one or more microorganisms. Performed in a gas lift reactor, bubble column reactor (BCR), membrane reactor, eg, hollow fiber membrane bioreactor (HFMBR), or trickle bed reactor (TBR), monolith bioreactor or loop reactor Also good. Also, in some embodiments of the invention, the bioreactor is fed with a first growth reactor in which microorganisms are cultured, and a fermentation broth from the growth reactor, and fermentation products (eg, ethanol and acetate). May include a second fermentation reactor in which most of the is produced.

According to various embodiments of the present invention, the carbon source for the fermentation reaction is synthesis gas resulting from vaporization. The syngas substrate is typically at least about 15 volume% to about 75 volume% CO, 20 volume% to 70 volume% CO, 20 volume% to 65 volume% CO, 20 volume% to 60 volume%. And a major proportion of CO, such as 20 volume% to 55 volume% CO. In certain embodiments, the substrate is about 25%, about 30%, about 35%, about 40%, about 45%, or about 50%, about 55%, or about 60% by volume. Of CO. Substrates with lower concentrations of CO, such as 6%, may also be appropriate, especially when H ₂ and CO ₂ are also present. In certain embodiments, the presence of hydrogen improves the overall efficiency of alcohol production. Gaseous substrate, some CO _2, for example, may comprise from about 1% to about 80% by volume of CO ₂ or 1 percent by volume to about 30% by volume of CO _2, also.

According to certain embodiments of the invention, the improved substrate stream CO content and / or H ₂ content can be concentrated prior to sending the stream to the bioreactor. For example, hydrogen can be concentrated using techniques known in the art such as pressure swing adsorption, cryogenic separation, and membrane separation. Similarly, CO is known in the art such as copper ammonium scrubbing, cryogenic separation, COSORB ™ technology (absorption on cuprous aluminum chloride in toluene), vacuum swing adsorption and membrane separation. It can be concentrated using techniques. Other methods used for gas separation and concentration are detailed in PCT / NZ2008 / 000275, which is fully incorporated herein by reference.

Typically, carbon monoxide is added to the fermentation reaction in the gaseous state. However, the method of the present invention is not limited to the addition of the substrate in this state. For example, carbon monoxide can be provided in a liquid. For example, the liquid may be saturated with a carbon monoxide containing gas and the liquid added to the bioreactor. This may be achieved using standard methodologies. As an example, microbubble dispersion generator (Hensirisak et.al. Scale-up of microbubble dispersion generator for aerobic fermentation; for this purpose , Applied Biochemistry and Biotechnol. be able to.

  It should be understood that in addition to the CO-containing substrate gas, an appropriate liquid nutrient medium must be supplied to the bioreactor in order for bacterial growth and CO to alcohol fermentation to occur. The nutrient medium contains enough vitamins and minerals to allow growth of the microorganisms used. Anaerobic media suitable for ethanol fermentation using CO as the sole carbon source are known in the art. For example, suitable media are the above-mentioned US Pat. Nos. 5,173,429, 5,593,886 and WO 02/08438, WO 2007/117157, WO 2008/115080, WO 2009/022925. No., WO 2009/058028, WO 2009/064200, WO 2009/064201, WO 2009/113878 and WO 2009/151342. The present invention provides novel media with increased effectiveness in supporting microbial growth and / or alcohol production in the fermentation process. This medium is described in more detail below.

  The fermentation should desirably be performed under conditions suitable for the desired fermentation (eg, CO to ethanol) to occur. Reaction conditions to be considered include pressure, temperature, gas flow rate, liquid flow rate, medium pH, medium redox potential, stirring rate (when using a continuous stirred tank reactor), inoculation level, in liquid phase A maximum gas substrate concentration to ensure that the CO is not rate limiting and a maximum product concentration to avoid product inhibition are included. Suitable conditions are WO 02/08438, WO 2007/117157, WO 2008/115080, WO 2009/022925, WO 2009/058028, WO 2009/064200, WO 2009/06201, WO 2009 / No. 113878 and WO 2009/151342, all of which are incorporated herein by reference.

  Optimal reaction conditions will depend in part on the particular microorganism used. In general, however, fermentation is preferably carried out at a pressure higher than ambient pressure. When operated at an elevated pressure, the transfer rate of CO, which can be taken up by microorganisms as a carbon source for ethanol production, from the gas phase to the liquid phase can be significantly increased. This in turn means that the retention time (defined as the liquid volume in the bioreactor divided by the input gas flow rate) can be reduced if the bioreactor is maintained at a pressure higher than atmospheric pressure.

  The advantages of performing gas to ethanol fermentation at high pressure are also described elsewhere in this specification. For example, WO 02/08438 describes a gas-to-ethanol fermentation carried out under pressures of 30 psig and 75 psig, with ethanol productivity of 150 g / l / day and 369 g / l / day, respectively. However, it has been found, for example, that fermentations carried out using similar media and influent gas composition at atmospheric pressure produce less than 10 to 20 times more ethanol per liter per day.

It is also desirable that the rate of introduction of the CO and H ₂ containing gaseous substrate is to ensure that the CO concentration in the liquid phase is not rate limiting. The ethanol product is consumed by the culture because CO can be the result of limited conditions.

  Fermentation products such as ethanol, or mixed streams containing two or more fermentation products are known in the art such as fractional distillation or evaporation, pervaporation, gas stripping and extractive fermentation including, for example, liquid-liquid extraction. You may collect | recover from fermentation broth by the method of this. The product may be diffused or secreted into a medium that can be extracted by phase separation.

  In certain preferred embodiments of the present invention, the one or more products are used to continuously remove a portion of the broth from the bioreactor, separate microbial cells from the broth (convenient filtration), and one or more from the broth. Is recovered from the fermentation broth by recovering the product. The alcohol can be conveniently recovered, for example, by distillation. Acetone can be recovered, for example, by distillation. All the acid produced may be recovered, for example, by adsorption on activated carbon. The separated microbial cells are preferably returned to the fermentation bioreactor. The cell free permeate remaining after removal of all alcohol (s) and acid (s) is also preferably returned to the fermentation bioreactor. Additional nutrients (such as vitamin B) may be added to the cell-free permeate to replenish the nutrient medium before returning to the bioreactor.

  In order to increase the adsorption of acetic acid on activated carbon, the pH of the broth should be readjusted to the same pH as the fermentation bioreactor broth before returning to the bioreactor, even if the pH of the broth is adjusted as described above. .

Product Recovery The fermentation reaction product can then be recovered using known methods. Representative methods include WO 2007/117157, WO 2008/115080, WO 2009/022925, US Pat. Nos. 6,340,581, 6,136,577, 5,593, No. 886, No. 5,807,722, No. 5,821,111. However, in brief, by way of example only, ethanol may be recovered from the fermentation broth by methods such as fractional distillation or evaporation, and extractive fermentation.

  Distillation of ethanol from the fermentation broth yields an azeotrope of ethanol and water (ie, 95% ethanol and 5% water). Absolute ethanol can then be obtained by using molecular sieving ethanol dehydration techniques known in the art.

  The extractive fermentation procedure involves the use of a water miscible solvent that presents a low risk of toxicity to the fermenting organism to recover ethanol from the dilute fermentation broth. For example, oleyl alcohol is a solvent that can be used in this type of extraction process. As oleyl alcohol is continuously introduced into the fermentor, the solvent rises and forms a continuous layer fed by extraction and centrifugation at the top of the fermentor. The water and cells are then easily separated from the oleyl alcohol and returned to the fermentor while the ethanol containing solvent is fed to the flash evaporator. Most of the ethanol is vaporized and condensed, while oleyl alcohol is non-volatile and is recovered for reuse in fermentation.

  Acetate produced as a by-product in the fermentation reaction can also be recovered from the fermentation broth using methods known in the art. For example, an adsorption system including an activated carbon filter may be used. In this case, it is preferred that the microbial cells are first removed from the fermentation broth using a suitable separation means. Numerous filtration-based methods for making cell-free fermentation broth for product recovery are known in the art. The cell-free ethanol-containing permeate and the acetate-containing permeate are then passed through a column containing activated carbon that adsorbs the acetate. Acetate in acid form (acetic acid) rather than salt (acetate) form is more easily adsorbed on activated carbon. Therefore, the pH of the fermentation broth is preferably reduced to less than about 3 times before passing through an activated carbon column to convert most of the acetate to the acetic acid form.

  Acetic acid adsorbed on the activated carbon can be recovered by elution using methods known in the art. For example, ethanol can be used to elute bound acetate. In certain embodiments, the acetate can be eluted using ethanol produced by the fermentation process itself. Since ethanol has a boiling point of 78.8 ° C. and acetic acid has a boiling point of 107 ° C., ethanol and acetate can be easily separated from each other using volatile based methods such as distillation.

  Other methods for recovering acetate from the fermentation broth are also known in the art and can be used in the process of the present invention. For example, US Pat. Nos. 6,368,819 and 6,753,170 describe solvents and cosolvent systems that can be used for acetic acid extraction from fermentation broth. Similar to the example of oleyl alcohol-based systems described for ethanol extractive fermentation, the systems described in US Pat. Nos. 6,368,819 and 6,753,170 are for extracting acetic acid products. Describes water-immiscible solvents / cosolvents that can be mixed with the fermentation broth, either in the presence or absence of fermentation microorganisms. The solvent / cosolvent containing the acetic acid product is then separated from the broth by distillation. Thereafter, acetic acid may be purified from the solvent / co-solvent system using a second distillation step.

  The product of the fermentation reaction (eg, ethanol and acetate) continuously removes a portion of the broth from the fermentation bioreactor and separates the microbial cells from the broth (convenient for filtration), either simultaneously or sequentially from the broth. It may be recovered from the fermentation broth by recovering more than one type of product. In the case of ethanol, it may be conveniently recovered by distillation, and acetate may be recovered by adsorption on activated carbon using the method described above. The isolated microbial cells are preferably returned to the fermentation bioreactor. Cell-free permeate remaining after removal of ethanol and acetate is also preferably returned to the fermentation bioreactor. Additional nutrients (such as vitamin B) may be added to the cell-free permeate to replenish the nutrient medium before returning to the bioreactor. Even if the pH of the broth is adjusted as described above to enhance the adsorption of acetic acid on the activated carbon, the pH will be similar to that of the broth in the fermentation bioreactor before being returned to the bioreactor. Should be readjusted.

General Embodiments of the invention have been described by way of example. However, it is to be understood that certain steps or steps required in one embodiment may not be required in another embodiment. On the contrary, the steps or steps included in the description of a particular embodiment can be advantageously used as appropriate in embodiments where they are not explicitly mentioned.

  Although the present invention has been broadly described with reference to any type of flow that can travel through or through the system (s) by any known means of transport, in certain embodiments, The biogas and the modified and / or mixed substrate stream are gaseous. One skilled in the art will appreciate that certain steps may be linked by suitable conduit means or the like that can receive and route the entire system flow. A pump or compressor may be provided to facilitate delivery of the flow to a particular stage. In addition, the compressor can be used to increase the pressure of the gas provided to one or more stages, eg, the bioreactor. As discussed above, the pressure of the gas within the bioreactor can affect the efficiency of the fermentation reaction that takes place therein. Thus, the pressure can be adjusted to improve the efficiency of the fermentation. Suitable pressures for general reactions are known in the art.

In addition, the system or process of the present invention may include means for adjusting and / or controlling other parameters as needed to improve overall process efficiency. For example, certain embodiments may include a determining means for monitoring the composition of the substrate stream and / or the exhaust stream (s). Further, certain embodiments control the delivery of substrate stream (s) to a particular stage or element within a particular system when the determining means determines that the flow has a composition suitable for the particular stage. Means for doing so may be included. For example, if the gaseous substrate stream contains low levels of CO or high levels of O ₂ that can be detrimental to the fermentation reaction, the substrate stream may be diverted away from the bioreactor. In certain embodiments of the invention, the system is for monitoring and controlling the destination and / or flow rate of the substrate stream so that a stream having the desired or appropriate composition can be delivered to a particular stage. Including means.

  Furthermore, it may be necessary to heat or cool a particular system component or substrate stream (s) before or during one or more stages in the process. In such a case, a known heating or cooling means may be used.

  Various embodiments of the system of the present invention are described in the accompanying drawings.

An alternative embodiment of the present invention is described in FIGS. As shown in FIG. 1, one embodiment of the present invention provides a system and method for producing one or more products comprising the following:
a. A pyrolysis zone 100 in which the biomass feedstock reacts under pyrolysis conditions to produce a gaseous substrate and at least one pyrolysis product selected from the group consisting of pyrolysis and charcoal.
b. A bioreactor 106 adapted to receive a gaseous substrate from the pyrolysis zone via conduit 102. Bioreactor 106 includes a culture of at least one carboxydotrophic acetic acid producing microorganism in a liquid nutrient broth. Bioreactor is operated under fermentation conditions to produce at least one fermentation product and effluent gas stream comprising H _2. At least one fermentation product is removed from the reactor via product conduit 108.
c. The effluent stream is sent from the bioreactor via a gas conduit to gas separation zone 112 where the hydrogen portion of the effluent gas stream is separated and sent via conduit 114 to hydrogenation zone 116.
d. The hydrogenation zone 116 is adapted to receive a hydrogen stream from the gas separation zone and to receive pyrolysis oil from the pyrolysis zone via conduit 104. The pyrolysis oil and hydrogen react under hydrogenation conditions to produce a hydrocarbon product having 6-20 carbons.

  FIG. 2 shows another embodiment for producing one or more products by fermentation of a gaseous substrate produced by liquefaction of biomass. According to one embodiment of the present invention, the biomass feedstock is sent to the roasting zone 200, which operates under conditions to produce the roasted biomass and the roasted gas stream 204. The roasted biomass is sent to the pyrolysis zone 202. The roasted biomass reacts under pyrolysis conditions to produce pyrolysis gas stream 206, pyrolysis oil and charcoal. At least a portion of the roasting gas stream 204 and pyrolysis gas stream 206 is sent to the bioreactor 210.

At least a portion of the pyrolysis oil and / or charcoal can be sent to the vaporization zone 208 as needed, where it is vaporized to produce a vaporized substrate comprising CO. The vaporized substrate can be sent to the bioreactor 210. Bioreactor 210 includes a culture of at least one carboxydotrophic acetic acid producing microorganism in a liquid nutrient broth. Bioreactor is operated under fermentation conditions to produce at least one fermentation product and effluent gas stream comprising H _2. The effluent stream is sent to the gas separation zone 212 where hydrogen is separated from the gas stream to produce a concentrated hydrogen stream. The concentrated hydrogen stream is sent to the hydrogenation zone 214. Hydrogenation zone 214 is adapted to receive pyrolysis oil and concentrated hydrogen stream from pyrolysis zone 206. The pyrolysis oil and hydrogen stream react under hydrogenation conditions to produce a hydrocarbon having 6-20 carbon atoms.

  The present invention has been described herein with reference to certain preferred embodiments to enable the reader to practice the invention without undue experimentation. However, one of ordinary skill in the art will readily recognize that many of the components and parameters may be altered or modified to some extent or replaced with known equivalents without departing from the scope of the invention. I will. It should be understood that such modifications and equivalents are incorporated herein as individually described. Titles, headings or the like are provided to enhance the understanding of the reader of this document and should not be construed as limiting the scope of the invention.

  The entire disclosure of all applications, patents and publications cited above and below, if any, are hereby incorporated by reference. However, references to all applications, patents and publications in this specification are recognized as constituting valid prior art or forming part of common general knowledge in all countries around the world. Or any form of suggestion and should not be construed as such.

Throughout this specification and all the claims that follow, words such as “comprise” and “comprising” are used in an exclusive sense, unless the context requires otherwise. Rather, it should be construed in a comprehensive sense, ie, “including but not limited to”.
The present invention includes the following embodiments.
[1] A method for producing at least one product from a gaseous substrate,
a. Converting at least a portion of the biomass feedstock into a gaseous substrate containing CO by a biomass liquefaction process selected from pyrolysis or roasting, a process performed in the liquefaction zone;
b. Sending at least a portion of the gaseous substrate to a bioreactor comprising a culture of at least one carboxydotrophic acetic acid producing microorganism, subjecting at least a portion of the gaseous substrate to anaerobic fermentation, and at least one fermentation product and Generating a waste stream containing a second biomass;
c. Separating at least a portion of the second biomass from the waste stream;
d. Sending a portion of the second biomass to the liquefaction zone;
Including methods.
[2] The method according to [1], wherein the gaseous substrate further contains CO ₂ and H ₂ .
[3] The method of [2], wherein the biomass liquefaction process produces at least one non-gaseous product, and the non-gaseous product is vaporized to produce a synthesis gas stream containing CO. .
[4] The method of [3], wherein at least a part of the synthesis gas stream is sent to the bioreactor.
[5] The method according to [1], wherein the at least one fermentation product is selected from the group consisting of ethanol, acetic acid, and 2,3-butanediol.
[6] A method for producing at least one product from a gaseous substrate,
a. Biomass feedstock in a pyrolysis zone operating under conditions to produce a gaseous substrate comprising CO, CO ₂ and H ₂ and at least one pyrolysis product selected from the group consisting of pyrolysis oil and charcoal Sending
b. At least a portion of the gaseous substrate is sent to a bioreactor comprising a culture of at least one carboxydotrophic acetic acid producing microorganism, and at least a portion of the gaseous substrate is anaerobically fermented to produce at least one fermentation. Producing a product, a waste stream comprising a second biomass and an effluent gas stream comprising hydrogen;
c. Separating at least a portion of the second biomass from the waste stream;
d. Sending a portion of the second biomass to the pyrolysis zone;
Including methods.
[7] The method of [6], wherein the effluent gas stream is sent to a separation zone operating under conditions to provide a hydrogen rich stream.
[8] The pyrolysis product is a stream rich in pyrolysis oil and hydrogen, and the pyrolysis oil is sent to a hydrogenation zone operating under conditions to produce a hydrogenation product. ] Method.
[9] The method according to [8], wherein the hydrogenation product is a hydrocarbon having 6 to 20 carbons.
[10] further sending the gaseous substrate from the pyrolysis zone to a separation zone operating under conditions to provide a CO ₂ rich stream and a concentrated CO and H ₂ gaseous substrate; Sending the concentrated gaseous substrate to the bioreactor. [6].
[11] is said pyrolysis product coal, said rich stream charcoal and the CO ₂ is fed to the reaction zone to produce a second substrate stream comprising CO, the second substrate flow the The method according to [10], wherein the method is sent to a bioreactor.
[12] The method of [6], further comprising first sending the biomass feedstock to the roasting zone before sending the biomass feedstock to the pyrolysis zone.
[13] A method for producing at least one product from a gaseous substrate comprising:
a. Sending biomass raw materials to the roasting zone to produce roasted biomass;
b. Sending the roasted biomass to a pyrolysis zone to produce a gaseous substrate comprising CO, pyrolysis oil and charcoal;
c. At least a portion of the gaseous substrate is sent to a bioreactor comprising a culture of at least one carboxydotrophic acetic acid producing microorganism, and at least a portion of the gaseous substrate is anaerobically fermented to produce at least one fermentation. Producing a product, a waste stream comprising a second biomass and an effluent gas stream comprising hydrogen;
d. Separating at least a portion of the second biomass from the waste stream;
e. Sending the effluent gas stream to a separation zone operating under conditions to provide a hydrogen rich stream;
f. Sending a portion of the second biomass to the roasting zone;
g. Sending the pyrolysis oil and hydrogen rich stream to a hydrogenation zone operating under conditions to produce a hydrogenated product;
Including methods.
[14] The method of [13], wherein the roasting process produces a gaseous byproduct stream comprising CO, and at least a portion of the gaseous byproduct stream is sent to the bioreactor.
[15] The method according to [13], wherein the charcoal is sent to a vaporization zone to be vaporized to produce a second gaseous substrate containing CO, and the second gaseous substrate is sent to the bioreactor. .
[16] The method according to [13], wherein the hydrogenation product is a hydrocarbon having 6 to 20 carbons.
[17] The method according to [13], wherein the carboxytotrophic acetic acid-producing microorganism is selected from the group consisting of Clostridium autoethanogenum, Clostridium ljundahlii, Clostridium ragsdalei, and Clostridium coskatii.

Claims (17)

A method for producing at least one product from a gaseous substrate, comprising:
a. Converting at least a portion of the biomass feedstock into a gaseous substrate containing CO by a biomass liquefaction process selected from pyrolysis or roasting, a process performed in the liquefaction zone;
b. Sending at least a portion of the gaseous substrate to a bioreactor comprising a culture of at least one carboxydotrophic acetic acid producing microorganism, subjecting at least a portion of the gaseous substrate to anaerobic fermentation, and at least one fermentation product and Generating a waste stream containing a second biomass;
c. Separating at least a portion of the second biomass from the waste stream;
d. Sending a portion of the second biomass to the liquefaction zone;
Only including, a second biomass consists cellular material from primarily culture methods. The method of claim 1, wherein the gaseous substrate further comprises CO ₂ and H ₂ .   The method of claim 2, wherein the biomass liquefaction process produces at least one non-gaseous product, and the non-gaseous product is vaporized to produce a synthesis gas stream comprising CO.   4. The method of claim 3, wherein at least a portion of the synthesis gas stream is sent to the bioreactor.   The method of claim 1, wherein the at least one fermentation product is selected from the group consisting of ethanol, acetic acid and 2,3-butanediol. A method for producing at least one product from a gaseous substrate, comprising:
a. Biomass feedstock in a pyrolysis zone operating under conditions to produce a gaseous substrate comprising CO, CO ₂ and H ₂ and at least one pyrolysis product selected from the group consisting of pyrolysis oil and charcoal Sending
b. At least a portion of the gaseous substrate is sent to a bioreactor comprising a culture of at least one carboxydotrophic acetic acid producing microorganism, and at least a portion of the gaseous substrate is anaerobically fermented to produce at least one fermentation. Producing a product, a waste stream comprising a second biomass and an effluent gas stream comprising hydrogen;
c. Separating at least a portion of the second biomass from the waste stream;
d. Sending a portion of the second biomass to the pyrolysis zone;
Only including, a second biomass consists cellular material from primarily culture methods.   The method of claim 6, wherein the effluent gas stream is sent to a separation zone operating under conditions to provide a hydrogen rich stream.   8. The pyrolysis product is a pyrolysis oil and the hydrogen rich stream, and the pyrolysis oil is sent to a hydrogenation zone operating under conditions to produce a hydrogenation product. the method of.   9. A process according to claim 8, wherein the hydrogenation product is a hydrocarbon having 6 to 20 carbons. In addition, sending the gaseous substrate from the pyrolysis zone to a separation zone operating under conditions to provide a CO ₂ rich stream and concentrated CO and H ₂ gaseous substrates; and 7. A method according to claim 6, comprising sending a gaseous substrate to the bioreactor. The pyrolysis product is charcoal, and the charcoal and the CO ₂ rich stream are sent to a reaction zone to produce a second substrate stream containing CO, and the second substrate stream enters the bioreactor. The method of claim 10, wherein the method is sent.   7. The method of claim 6, further comprising first sending the biomass feedstock to the roasting zone before sending the biomass feedstock to the pyrolysis zone. A method for producing at least one product from a gaseous substrate, comprising:
a. Sending biomass raw materials to the roasting zone to produce roasted biomass;
b. Sending the roasted biomass to a pyrolysis zone to produce a gaseous substrate comprising CO, pyrolysis oil and charcoal;
c. At least a portion of the gaseous substrate is sent to a bioreactor comprising a culture of at least one carboxydotrophic acetic acid producing microorganism, and at least a portion of the gaseous substrate is anaerobically fermented to produce at least one fermentation. Producing a product, a waste stream comprising a second biomass and an effluent gas stream comprising hydrogen;
d. Separating at least a portion of the second biomass from the waste stream;
e. Sending the effluent gas stream to a separation zone operating under conditions to provide a hydrogen rich stream;
f. Sending a portion of the second biomass to the roasting zone;
g. Sending the pyrolysis oil and hydrogen rich stream to a hydrogenation zone operating under conditions to produce a hydrogenated product;
Only including, a second biomass consists cellular material from primarily culture methods.   14. The method of claim 13, wherein the roasting process produces a gaseous byproduct stream comprising CO, and at least a portion of the gaseous byproduct stream is sent to the bioreactor.   14. The method of claim 13, wherein the charcoal is sent to a vaporization zone and vaporized to produce a second gaseous substrate containing CO, and the second gaseous substrate is sent to the bioreactor.   14. A process according to claim 13, wherein the hydrogenation product is a hydrocarbon having 6 to 20 carbons.   14. The method of claim 13, wherein the carboxydotrophic acetic acid producing microorganism is selected from the group consisting of Clostridium autoethanogenum, Clostridium ljundahlii, Clostridium ragsdalei, and Clostridium coskatati.